In fact, cryptocurrency is only one tool that can be used among several other options, and gambling is one of the mediums that can be used to launch money laundering activities. It's just that when cryptocurrency is used as a medium to commit criminal acts, then cryptocurrency anonymity will be blamed, especially decentralized crypto which is not issued by any central authority making it difficult for government interference.
I think the government's inability to be able to control the blockchain system is what causes them to blame cryptocurrency and its system.